Boeing knew about problems with the 737 Max aircraft’s alert system back in 2017 but did nothing about it for more than a year, according to a company statement released on Sunday.
Boeing said in the statement that it made an alarm alerting pilots to a mismatch of flight data optional on the 737 Max instead of standard, but insisted that the lack of display brought no safety risk.
In 2017, well before the fatal Lion Air crash in Indonesia last October, engineers discovered the 737 Max display software didn’t meet the requirements for the angle-of-attack disagree alert, which flashes if an aircraft’s angle-of-attack sensors transmit faulty data about the pitch of the plane’s nose.
The Federal Aviation Administration (FAA) said on Sunday that Boeing waited 13 months before reporting the lack of the alert function in November 2018, following the Lion Air crash.
Though they criticized Boeing for not disclosing the problem fast enough, the FAA backed Boeing’s assessment after the Lion Air crash that the lack of alert posed a “low-risk” to the safety of commercial aircraft.
U.S. aircraft manufacturer Boeing is working desperately to reprogram the software update to the Maneuvering Characteristics Augmentation System (MCAS) of 737 Max aircraft, two of which crashed within the last year, killing a total of 346 people on board.
Investigators have zeroed in on the MCAS flight control system as a possible factor behind the two deadly tragedies, after which many countries including the United States grounded the aircraft.